Pbartender said:
Apparently, the skeletons have a rudimentary intelligence... Just enough to obey commands in the same way a well-trained animal might, and fight in a reasonably efficient manner.
Perhaps the "fluff" of a mark is simply that in some cases the attacker is so aggressive that it's harder to devote your attention elsewhere when retaliating. That would explain marks from less intelligent monsters... they're not necessarily using any tactics or tricks in influence the target, but they're just so very tenaciously single-minded in their attacks that its difficult to ignore them.
To expand on this, I don't have any difficulty with marking, either from a conceptual in-game viewpoint, or, as far as I can tell, from a tracking standpoint.
A creature that "marks" you is basically committing to attacking you. Put another way, it's keeping an eye on you. That skeleton warrior has decided to focus on one target, in its simple-minded way. You can't simply ignore it, because it will harrass you, making it difficult for you to attack another target. In other words, the creature staring intently at you and poking its weapon in your direction is the one "marking" you. That takes care of how you describe it to the players and how their character's perceive it.
From a tracking standpoint, it's simple: the last creature capable of marking that attacked you leaves you "marked" until the next turn. I can see a couple soldiers (or defenders) trading off who they "mark" as a tactical game to play with their opponents.
Yes, it makes for a tactical exchange. However, it's really no more complicated than running a low-level caster. Consider this somewhat simplistic exchange, involving a fighter and a paladin vs. two hobgoblin soliders:
Fighter: "I attack the hobgoblin on the left (A), marking him."
Paladin: "I attack the hobgoblin on the right (B), marking him."
DM: "Hobgoblin A notices the fighter and attacks. He counter-marks you. A battle is joined. Hobgoblin B counter-attacks the paladin...and you're also marked."
(a round or two later, the fight is still going...)
Fighter: "Time to change tactics....I'm shift, suck up the penalty and attack B instead. He's now marked..."
Paladin: "Sweet...I shift and mark A..."
Obviously, with two guys, this is pointless...but if you involve a striker, it could get interesting...
Quite honestly, I just don't see what's so complicated. *shrug*
Maybe it's harder in play. Guess I'll find out in June.